As a member for releasing a heat generated from an electronic component and the like in an electronic device to the outside, currently used is, for example, a thermally conductive molded article that includes a thermally conductive filler, with using a styrene-based elastomer as a base polymer, as shown in Patent Document 1. A thermally conductive molded article of this type is used, for example, by being interposed between an electronic component mounted on a substrate and a heat radiator such as a heat radiation plate, to transfer a heat generated from the electronic component to the heat radiator.
When a gap is formed between the thermally conductive molded article and an electronic component or between the thermally conductive molded article and a heat radiator, a heat radiation efficiency is lowered. Therefore, a thermally conductive molded article is required to have a flexibility (a low hardness property) that allows the molded article to follow a form of an electronic component and the like. A thermally conductive molded article is also required to have an insulation property, from a viewpoint of ensuring a normal operation of an electronic component and the like.
In this connection, as the thermally conductive filler, an expandable graphite is currently used.